Bradley Marchand (24:06)
100 anybody can do that. We call it being a silent witness. So I love knowing that potentially my DNA could help solve a crime. Now one thing I do talk about is not only is your DNA uploaded into that database helpful for now, but that could Go on years after your death that your DNA could still be used to solve genealogical mysteries or even crimes. I mean, think about how cool would it be if you knew that, you know, your DNA was the thing that helped solve a serial killer, or your DNA was used to identify your third cousin that you've never heard of that went missing back in the 70s. But your DNA is the key piece of DNA that is used to solve that person's identity after. I'm getting a little distracted because I want to get back to explain how this is done because it is kind of interesting to me, but it is kind of probably foreign to most of your listeners. Once the DNA is uploaded, we get a match list of people that share DNA and it tells you how much DNA they share. And with the different databases, we can play with it where we can look at how much DNA does that person share, share with this other person to know how closely are they all related? It's kind of like a, like a spider web of who's related to who. So we have an identity of somebody that we're trying to figure out, but we have the identities of multiple of their relatives. So some of them might be distant relatives that share just a small portion of DNA and others might be closer, maybe a second or third cousin. In general, we really would love to, to always have second and third and fourth cousins because those are oftentimes extremely helpful and realistic for us to find. It's rare that we're going to upload a DNA profile for a serial killer and have their parent or grandparent or child already have taken a test. It's much more realistic to think, oh, their second cousin twice removed or their half third cousin has taken a DNA test, has then uploaded it. So we then build the family trees of a bunch of these different relatives. For one of my most recent cases, I ended up having to build about 20 people's family trees so 20 different DNA matches to then find out how they are related to each other and then determine if those people are probable ancestors of the person of interest. So let's do a short scenario. Let's say we're looking for a Jane Doe. Her body was found in 1975. They have part of her DNA still saved. So we can still process her DNA for this newer test, this different type of test called a SNP test. We do that and we find, let's say, say let's do a good example. Let's say we find three or four second cousins. We will build all of those second cousins family trees and look for ways that they overlap. So let's say we find two second cousins and they share a set of great grandparents. Depending on how much DNA they share with the Jane or John Doe helps us to determine how many generations we maybe have to go back. But in general, if they're second cousins, they're going to share great grandparents. We then take those great grandparents and then we trace all of their descendants down until it's until as far as we can go or until we know approximately when that Jane Doe was born. So we take those descendants down, then we look at another group. Let's say we have a third cousin and a fourth cousin who are DNA matches. We build their trees to find out how they're related to each other and then we find their common ancestors. Then we trace their descendants going down, looking for ways from those two groups where they overlap. So, so maybe a great grandchild of the first group married a great, great, great granddaughter of the second group. Then we see where those two groups overlap. And depending on how closely that person might be related to the individual, helps us to determine are we on the right track. But generally if we find out how two groups intersect, that's a pretty good chance that we're on the right track. So then if we're looking for a Jane Doe, we might start looking at known missing persons cases. We might start looking at people in the family tree who just kind of disappear from records because not all Jane and John does are actually reported missing or if they were reported missing, it might have been lost since the digital age. So that missing persons file might be in a small police record, on paper, in the back of a filing cabinet and has not been posted onto some of the national databases. And they might not have any living relatives who have provided their DNA for codis. If they had, the case wouldn't have ever had to go to FIG because it would have been solved through a CODIS match. So it generally involves building a whole lot of family trees, looking for ways that they connect, building down from those connections, knowing that our person of interest is probably amongst their, you know, amongst that group. That doesn't factor in things like adoptions or non parental events or situations where, you know, it's not ideal. And in most situations we don't have multiple second cousins that we're working with. One of my current cases, the closest match is probably a fourth or a fifth cousin, meaning that I have to trace back to fifth and sixth great grandparents looking for common connections. And you can imagine when you're building a family tree and you have to go back to fifth great grandparents. Just how many people we're talking about can be pretty daunting because you have to do the math real quick. You have two parents, four grandparents, eight great grandparents, 16 great greats, 32 great great greats, 64 great great great greats, and then 128, if I'm doing the math right, fifth great grandparents.
